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Objective: This study was to determine if calcium fortification yields a higher price per serving in grocery store products. Researchers compared store brand to national brand grocery products in relation to cost in order to examine if calcium values were similar between store brand and national brand products. Methods: A total of 112 store brand and 211 national brand grocery products were collected from three low (national chain store), middle and high priced (Virginia and North Carolina regional store) grocery venues. Products were compared using price and calcium percentage per serving. ANOVA was used to determine between store brand and national brand for price per serving and calcium content, and between grocery venues. Results: National brand fortified products had a significantly lower mean price per serving when compared to national brand non-fortified products (p = 0.0002). There was no statistical difference between store brand fortified and non-fortified products (p = 0.9256). Low priced store brand products had the lowest mean price per serving ($0.34 ±0.24). Conclusions: This study found store brand products have similar calcium content as national brand products. Product cost was lower at low priced store compared to middle and high priced stores. 相似文献
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鸡蛋壳制备乙酸钙冰雪融化剂的研究 总被引:5,自引:1,他引:4
以鸡蛋壳为原料,对高温煅烧分解蛋壳、中和法制备乙酸钙(CA)的最佳反应条件进行了研究,试验结果表明:在所选参数下,其产量最大.即反应温度为50℃,配料摩尔比为CaO:HAc=1:2.8,乙酸浓度为15 mol/L,石灰乳浓度(以氧化钙计)为1.3 mol/L.产品融冰试验表明:CA在环境温度为-10℃以上使用时,其融冰效果较好. 相似文献
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Policy discussions on agricultural pollution problems characterize prevention as more cost effective and precautionary than ex post treatment. We derive conditions under which treatment alone is more cost effective in situations involving multiple sources of emissions, multiple sites affected, and a commonly used precautionary approach to uncertainty. We also show that a greater degree of precaution can result in less reliance on prevention. An empirical case study indicates that treatment alone is the most cost-effective means of dealing with nitrate in most Maryland community water system wells. The use of leaching prevention measures is restricted to the most intensive poultry producing areas. The incremental cost of precaution is substantial. 相似文献
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文章提出“碳化工艺连续化、活化剂复合化、活化技术组合化、活化温度常温化、干燥技术组合化和系统工程化”,应成为我国超细碳酸钙生产技术未来发展的主要方向,并论述了我国目前超细碳酸钙生产技术的现状,用连续鼓泡碳化工艺来改造现有碳化工艺,并提出了超重力反应结晶法的完善办法。 相似文献
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萤石的经典分析方法是将碳酸钙和氟化钙分离后,在用滴定法分别进行滴定分析,这种分析方法较为准确,但周期长、效率差、多次滴定易产生误差,无法满足快速大量测定样品的要求。本文探讨通过采用滴定-原子吸收法相结合方式测定萤石中氟化钙、碳酸钙的含量,可在大幅缩短测定时间的同时避免二次滴定产生的误差提升结果准确度,并可用于满足大量萤石样品的分析需求。 相似文献
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通过室内土柱实验模拟氮素在不同沉积物的潜流带中迁移转化途径,选取粗砂、细砂、粉砂三种介质,以浓度为65.5mg/L的硝酸钾溶液为原水,研究硝态氮在不同沉积物的潜流带中的环境行为;再通过补充碳源,研究碳源对氮的迁移转化过程的影响。实验结果表明,在不同的沉积物介质中,氮的迁移转化不同,主要受介质孔隙度和介质中有机质的制约。由于粉砂介质中孔隙度较小,有利于微生物的附着,且有机质含量较多,反硝化作用和异化还原作用强烈,所以硝酸盐氮下降的最多,而在粗砂介质中孔隙度相对较大,不利于微生物附着,且有机质含量相对较低,反硝化作用和异化还原作用较弱,硝酸盐氮下降的较少。而添加碳源后,反硝化作用和异化还原作用增强,三根柱子中的硝酸盐氮都降到很低的值,说明碳源对潜流带中硝态氮的去除起着重要的作用。 相似文献
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汤小胜 《黄石理工学院学报》2009,25(6):26-29
文章介绍了地下水中硝酸盐污染来源,并阐述了地下水中硝酸盐污染的三种修复技术,即物理化学修复技术、化学修复技术和生物修复技术,同时还回顾了利用这些修复技术治理硝酸盐引发的地下水污染方面的研究成果,最后提出了防治地下水中硝酸盐污染的建议。 相似文献
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研究了利用粉煤灰合成4A沸石的工艺过程,通过正交试验考察了钠铝摩尔比、硅铝摩尔比、水钠摩尔比、晶化温度和晶化时间不同条件的变化对所合成样品钙交换能力的影响,选定了最佳工艺条件,合成的样品具有良好的钙离子交换能力和结晶度。 相似文献